Electric clock



Feb. 9, 1937. POOLE 7 2,070,238

ELECTRIC CLOCK Filed Oct. 17, 1931 Patented Feb. 9, 1937 UNITED STATES- PATENT OFFICE ELECTRIC CLOCK Arthur. F. Poole, Ithaca, N. Y., by Maryline B. Poole, administratrix of said Arthur F. Poole, deceased, assignor to Maryline B. Poole, Ithaca, N. Y.

Application October 17, 1931, SerialNo. 569,457

Claims. (Cl. 5826) My invention is an electric clock preferably and are current mains serving to conduct an designed to be actuated from a source of regualternating current from a generator 92 driven lated alternating current. By regulated current by a prime mover 9|,- preferably regulated by Imean an alternating current whose frequency a master clock 90. Joined to these mains by is closely regulated to a master clock so that the the conductors I'Zand I3, is an electromagnet l4 5 average, number of cycles sent out in a given built of laminations l5 held by bolts l6 and havtime is constant, usually 60 cycles per second. ing a winding H. An insulating plate |8,is

Oneof the objects of myinvention is to elimimounted on the magnet 4 and carries a reed nate the synchronous motor commonly used in IS tuned by a weight 20 to vibrate cycles per 10. clocks run by regulated current, replacing said second. A contact point 2| insulated fromthe 10 motor by an electrical frequency reducing deframework by a. plate 22 is provided to close a vice to hold a clock of ordinary construction circuit (presently to be described) at each cycle in step with said current. Another object of of the reed 9.

my invention is ,the use of tuned reeds Vibrating Similarly, there is a second laminated electroin step with the regulated current and by a novel magnet 23 whose laminations are held by bolts '15; heterodyne device, producing a current of low having a winding 25 joined by conductors 2 6 frequency which is .used to hold a clock in step and 2| ,to the mains l0 and II. The magnet 23 therewith. A further object of my invention is is also provided with an insulator 28 on which is in theuse of a triode to govern the circuit serva reed 29 tuned by a weight 30 to 12 vibrations 2O ing to heterodyne the two reeds to the end that persecond and also provided with a contact 3| its action be made certain and reliable. Another mounted on an insulating block 32. Since both object of my invention is the novel means used 10 and 12 are integral sub-multiples of 60 both to hold a balance instep with a current of reeds will vibrate at their tuned frequencies from nearly the. same frequency as the period of said the 60 cycle current. I prefer to make the reeds 25 balance. The above and. other objects of my polarized either from a permanent magnet (not invention will be apparent to those skilled in the shown) or by making them of a steel suitable to art from thefollowing specification and will be be permanently magnetized. set forth in the claims. Obviously, if one were to join the contacts 2] In the. preferable form of my invention, deand. 3| in series with a source of electromotive 30 scribed herein, I take a regulated current of 60. force, one would get a current of two impulses 30 cycles per second and from it vibrate two tuned per second; however from considerations of the reeds, one at the sub-multiple frequency of 12 life of the contacts 2| and 3|, I prefer for this persecond and the other at 10 per second. The purpose, to use a triode 39 having a plate 40 a reeds are provided with means to heterodyne grid 4| and a filament 38. A transformer 36 their frequency and produce a current of two has a primary Winding 33 connected by con- 35.

cycles per second. This current is led through ductors 34 and 35 with the mains I0 and II. A an electromagnet Whose armature consequently winding 3'. supplies current to thev filament 38 makes two strokes per second and moves one end and a second winding 42 is joined by a wire 43 of a spring. The other end of this spring is to a winding 44 on an electromagnet 45 having attached to a balance wheel of a clock thus forcan armature 46 swung between the poles thereof 40 ing the balance to keep in step with said current. and held by. a spring 88. against a stop 89;. The

The clock may be wound by the 60 cycle cur- Winding 44 is joined to the plate 40. by a wire rentif desired and I have showna device suit- 41. The, grid 4| ,is joined by a wire. 48' to the able for this purpose, altho such winding de-. contact 3| and the reed 29 1s connected to the 5 viceforms no part of my present invention since reed l9 by a wire 49. A wire 50 joins the conit is shown in my issued Patent 1,328,247 of:1920. tact 2] to a winding 5| of the transformer, 36 In my herein described invention so long as the which is so designed to put a negative bias on 60. cycle current is on, the clock is held in step the grid 4| when the contacts 2| and 3| are both with it. When the current is interrupted the closed. The usual grid leak (not shown) is clock, which is regulated to keep approximate placed between the grid and filament. 50; time, goes on until the current is resumed or the It is obvious that when the grid circuit is powerstored in the clock mainspring has been closed, that is when both contacts 2| and 3| used. are closed, nocurrent will flowin the plate cir- My invention may be best understood byrefercuit since the negative biasof the grid will preenceto the diagrammatic drawing in which l0. vent it. When either of the contactsjl or 3| 55;

are open then plate current will flow and the magnet 45 will be excited and attract its armature. The plate current will be composed of short impulses but the integral of these impulses will vary in magnitude with a period of two per second. The armature 46 is made to have a large moment of inertia so that it will not respond to the short current impulses but will respond to the impulses of a period of two per second. The armature 46 is connected by a link 42 to a lever 53 on a shaft 54 and has a rod 55 therein to which is secured a hairspring 56 which is fastened to a balance staff 51 co-linear with the shaft 54. The staff 51 carries a balance wheel 58 provided with timing screws 59 and a roller pin 60. The armature 46 will make two oscillations per second; since the balance is timed to make two oscillations per second also, the balance will be heldin step with the armature 46 which in turn is held in step with the regulated current. Thus every beat of the balance, the hairspring 56 will be given an accurate impulse in a clockwise direction by action of the armature 46 being pulled away from the stop 89 to the position shown by dotted lines. After each long (2 per second) current impulse has ended, the armature 46, impelled by the action of the spring 88, will return to its original position against the stop 89.

The remainder of the structure is conventional clock practice and will be obvious to those skilled in the art by a brief description. The balance 53 is driven by a fork with counterweight 62 on a shaft 53 on which is a pallet 64 driven by a scape wheel 65. The usual train of wheels, 66, 61 and 68 joins the scape wheel 65 to the center wheel 68 which is on a shaft 69 on which is the minute hand 10. An hour hand H is driven from 69 by the usual motion work (not shown). I have provided my clock with a conventional electric wind consisting of a wheel 12 which drives the center wheel 68 and is on a shaft '53 to which is fastened a mainspring'l l whose outer end is fastened to a slip spring E5 in a barrel 16. The barrel 16 has teeth H driven by a train of gears 18, 19, 83, BI, 82, and 83. The gear 83 is on a shaft 84 of an induction motor 85 connected to the mains l0 and II by the wires 86 and 81. 85 winds the outside of the spring 14 faster than the inside runs down. The excess wind is taken care of by the slip spring i5.

While I have described my invention as used with a 60 cycle current and by reeds of a frequency of and 12 producing a current of 2 to control a clock whose balance has a frequency of 2, these particular frequencies are merely the preferred ones, others may be used tosecure the same result and will be within the scope of my herein described invention. In some of the following claims I have used the term clock hands to denote any means by which time may be read from a clock. Obviously, in a recording meter the position of the record sheet would give an indication of the time of the clock and such a device is within the scope of my invention despite the fact that the clock may be without hands.

Many changes may be made in the precise structure herein shown without departing from the spirit of my invention since I claim:-

1. In an electric clock the combination of a source of alternating current, a reed tuned to a submultiple of the frequency of said alternating current, a second reed tuned to a second sub- The motor multiple of the frequency of said alternating current, electromagnetic means operated by said current to operate said reeds, a set of contacts operated by said first reed, a second set of contacts operated by said second reed, a circuit energized by said source of alternating current and including said first set of contacts and said second set of contacts, whereby a low frequency current is allowed to flow in said circuit by reason of the joint action of said two sets of contacts, clock hands, means to drive said clock hands, and means in said circuit whereby said hand driving means is held in step with said source of alternating current.

2. In an electric clock the combination of a source of alternating current, a reed tuned to a submultiple of the frequency of said alternating current, a second reed tuned to a second submultiple of the frequency of said alternating current, electromagnet means energized by said source of current to vibrate said reeds, a set of contacts operated by said first reed, a second set of contacts operated by said second reed, a triode, a circuit energized by said source of alternating current including said two sets of contacts and the grid of said triode whereby a low frequency current is allowed to flow in said circuit, an electromagnet in the plate circuit of said triode, clock hands, means to drive said clock hands, and means operated by said electromagnet to hold said driving means in step with said source of alternating current.

3. In an electric clock the combination of a source of alternating current, a reed tuned to a submultiple of the frequency of said alternating current, a second reed tuned to a second submultiple of the frequency of said alternating current, electromagnet means energized by said source of alternating current to vibrate said reeds, a set of contacts actuated by said first reed, a second set of contacts actuated by said second reed, a circuit energized by said source of alternating current and including said sets of contacts whereby a current of a submultiple frequency of said alternating current is allowed to flow in said circuit, an electromagnet in said circuit, a vibrating balance, and an elastic connection between said electromagnet and said balance to force said balance to vibrate in step with said source of alternating current 4. In an electric clock, the combination of a source of alternating current, a current controlling means comprising a reed tuned to a submultiple frequency of said alternating current, a set of contacts actuated by said reed, a second reed tuned to a second submultiple frequency of said alternating current, a second set of contacts actuated by said second reed, and electromagnetic means energized by said source of alternating current for causing said reeds to vibrate, a circuit energized by said source of alternating current and including the said two sets of contacts of said current controlling means, whereby the resultant frequency in said circuit is determined by the frequencies of said two reeds, clock hands, means to drive said clock hands, and means in said circuit operated by said resultant frequency current for holding said hands in step with said alternating current.

5. In an electric clock the combination of a source of alternating current, a current control- ;ling means comprising a reed tuned to a submultiple frequency of said alternating current, a set of contacts actuated by said reed, a second reed tuned to a second submultiple frequency of the resultant frequency in said circuit is determined by the frequencies of said two reeds, clock hands, means to drive said clock hands, and an electromagnetic means in said circuit operated by said resultant frequency current for holding 5 said hands in step with said alternating current.

ARTHUR F. POOLE. 

